Index: Modules/Compiler/G95-Fortran.cmake
--- Modules/Compiler/G95-Fortran.cmake.orig
+++ Modules/Compiler/G95-Fortran.cmake
@@ -1,8 +1,13 @@
 string(APPEND CMAKE_Fortran_FLAGS_INIT " ")
-string(APPEND CMAKE_Fortran_FLAGS_DEBUG_INIT " -g")
-string(APPEND CMAKE_Fortran_FLAGS_MINSIZEREL_INIT " -Os")
-string(APPEND CMAKE_Fortran_FLAGS_RELEASE_INIT " -O3")
-string(APPEND CMAKE_Fortran_FLAGS_RELWITHDEBINFO_INIT " -O2 -g")
+if(DEFINED ENV{MODCMAKE_PORT_BUILD})
+  string(APPEND CMAKE_Fortran_FLAGS_DEBUG_INIT " -g")
+  string(APPEND CMAKE_Fortran_FLAGS_RELWITHDEBINFO_INIT " -g")
+else()
+  string(APPEND CMAKE_Fortran_FLAGS_DEBUG_INIT " -g")
+  string(APPEND CMAKE_Fortran_FLAGS_MINSIZEREL_INIT " -Os")
+  string(APPEND CMAKE_Fortran_FLAGS_RELEASE_INIT " -O3")
+  string(APPEND CMAKE_Fortran_FLAGS_RELWITHDEBINFO_INIT " -O2 -g")
+endif()
 set(CMAKE_Fortran_MODDIR_FLAG "-fmod=")
 set(CMAKE_Fortran_VERBOSE_FLAG "-v")
 set(CMAKE_Fortran_FORMAT_FIXED_FLAG "-ffixed-form")